GENERAL OBJECTIVES: (1) Elucidation of the mechanism of squalene-2,3-oxide cyclization to lanosterol, the parent of all sterols, (2) identification of new intermediates in the enzymic conversion of farnesyl pyrophosphate to squalene, the parent of squalene-2,3-oxide. Immediate, current goals are proof by synthesis of the structure of an unusual, abnormal, enzymically-produced, sterol-like product which has a bearing on (1) above; and synthesis by organic means of one of the possible, projected intermediates referred to in (2) above, preparatory to enzyme experiments.